hi - Im in discussion with a guy in Rhode Island who has a complete, non seized Corvair motor in his place of work: a junkyard. Apparently the motor has been stored inside for a number of years in a dry building. He wants $200 for it - knows zero about the engine. Where it came from, what car it was in, nothing. But he said the motor does turn, so its not seized. It looks to be a 110 motor but Im not sure. I asked him to give me the engine code, located by the oil filler tube. He said it says: gm3 3851864 gm. Any idea what this code translates out to? See pic of motor below. Thank you for any info you can provide!

The engine appears to be a 65-67 110 or 95 engine - powerglide bell housing. The "mystery code" is no mystery at all; it's the casting number for the oil filter / alternator adapter casting. Ask you friend to look 1" forward and 1" down. Clear that little area with the tip of a screwdriver and read the engine code.

The part number you supplied is not the engine serial number. it is a part number from the oil filter/alternator adaptor casting component that is adjacent to where the serial number would be, as shown in the photo below.

I have included some images below that would provide additional clues about this engine, including cylinder head casting numbers and distributor numbers. The engine appears to be a 110 hp engine from a 1965-67 Corvair, based on the alternator, engine mount design, magnesium cooling fan, etc. The distributor number is a minor clue, since distributors can be easily swapped. There is no fuel return line on the fuel pump (added in 1968-69). The best clue is often the cylinder head casting number. If a harmonic balancer is present, that usually indicates a 164 CI engine rated at 110 hp or greater. A cast pulley would normally indicate a 95 hp engine.